Abrasive cutting machine



Aug. 10, 1937. D. LEWIS El AL 20,465

ABRASIVB CUTTING MACHINE Original iiied April- 18, 1934 2 Sheets-Sheet 1INVENTORS DARrREY LEW/6 Warn/0 L. WALM. BY WALTER a. LAMAR")?! ATTORNEY4 Aug. 10, 1937. o. LEWIS El AL 20,466

ABnAsivs cum-ms MACHINE Origipal Filed April 18, 1934 2 Sheqts-Sheet 2INVENTORS .DARTREY LEW/.5, W/LFRID L. wALsH, BY WALTER B.LA.smR,-m

Rea Au 10, 1937 UNITED STATE aaaasrvn co'r'rmo Dal-trey Lewia'Boston,and Wilfrid 1.. Walsh,

Cambridge, Mass,

and Walter B. Lashar, Jr.,

Failfield, Conn, assignors to American Chain '& Cable Company, 1m,Bridgeport, Conn, a corporation of New York Original No.

2,031,052, dated February 18, 1930,

Serial No. 721,128, April 18,1934. Application,

for reissue December 14,

9 Claims.

This invention relates to animproved method and apparatus for cuttingvarious substances, more particularly those of a brittle nature,although it is usefully applied, to the cutting of any hard substancewhetheror not having the :haracteri'stic.of brittleness, such. asvarious steels and other metals, plastic compositions, hard rubber, etc,The invention involves, as its principal, feature, the cutting of suchmaterials 10 while they are subject to the action of a stream of wateror other suitable liquid as distinguished from other processes recentlydeveloped wherein they are submerged in a body of water. We are aware ofthe fact that it has already-been found that, when cutting metals with athin abrasive wheel, it is of great advantage to submerge'the -material.in a liquid-more commonly waterthe result of which is a smooth, cleancut with a substantially perfectly plane section. without burrs on itsedges and without any deleterious effects from burning or undue heating.We have found that, while submergence of the materials during cuttingwith wheels of the type abovementioned is highly advantageous, there aare many cases in which complete submergence or immersion can bedispensed with and a stream of water directed on the work in the regionof cutting, provided such stream of water be of suitable volume and beproperly directed and con- I With the foregoing and other objects inview,

the invention consists in a certain method and improved means forcarrying out the method, as will be more clearly disclosed in connectionwith the accompanying drawings, but it is to be understood that we arenot limited to' the specific apparatus shown, it being quite feasible tocarry out the method in various other apparatus.

Referring'to the drawings,

Fig. 1' is an elevation of the machine partly in section; r

Fig. 2 is a view'on the line 2-2 of. Fig. 1; and Fig. 3 is a plan viewon the line 3-3 of Fig. 1.

These drawings show the embodiment of the 45 invention in a machinewhich has proven very efficient in carrying out the process referred to.It comprises a bed III which may be provided with vertical peripheralwalls II to form a reservoir or container for water or other liquid em-50 ployed in the cutting operation, as will be hereinafter moreparticularly pointed out. This bed or container maybe mounted on anysuitable support such as the pedestal ll. The container may be providedwith rearwardly extending 55 brackets IS on which may be pivotallymounted,

1936, Serial No. 115,888

as by a shaft 15, a frame ll carrying the thin abrasive cutting wheelindicated atjll and the power means for driving this wheel, such as anelectric motor It. In theprcsent instance, the wheel is removablymounted on a shaft 20 running in bearings 2| in the frame, I! and isdriven by a suitable flexible drive such as a V-belt drive .22 runningover pulley 23 on the shaft 20 and also on a drive pulley (not shown)carried by the motor shaft in theusual manner. It is' also preferred toprovide means for adjusting the tightness of this belt drive, and, inthe present instance, the motor is carried on a frame 25 secured tofanupright bracket 26 pivoted in the frame I'l at ll between arms 28. Thisbracket 26 also has a lug 29 provided with an arcuate slot ill struckwith the pivot 21 as its center. ,An adjustable clamping bolt 3| carriedby the lug 32 on the frame ll provides a means for bolding the bracket26 in adjusted position.

. It will be noted that the wheel II with its mounting means and themotor I9 are mounted on opposite sides of the pivot Ii of the frame I1,and therefore these elements counterbalance each other so that, inswinging the frame to move the wheel to and from the work, very littleeffort is required. Preferably the motor should overbalance the wheelsomewhat so as to retain the wheel in the upright position-that is, awayfrom the .work between cutting operations. An adjustable limit stop iscarried by the frame H to limit downward movement of the wheel toprevent its being shifted further, than necessary for severing theparticular section being out. In the construction shown, this comprisesa rod 33 threaded into 9, lug 34 on the frame and having a crank handle35 whereby it may be adjusted. At its lower end it is adapted to engagean upwardly; extending. stop wall "carried by the container Hi to limitdownward movement of the wheel. The frame Il may to shift the wheel toand from the work by any suitable handle Ila adjustably secured to theframe at l'lb.

The wheel is preferably enclosed in a suitable safety guard so that,should it break, there will be no flying pieces to injure the operator.This guard is illustrated as a sheet metal member 42 extending over andenclosing the wheel and including an enclosing wall 43 on one side. Onits opposite side it has an opening ll of sumcient diameter to permitinsertion and removal of the wheel for application driving shaft 20.After this opening is closed by the wheel is applied, a coverplate l5,prefbe rocked on its pivot to and removal from the erably detachablysecured in position by any suitable means. The rear wall 3 is providedwith an arcuate slot 41 through which the shaft 20 extends and permitsup and down movement of the wheel. The guard may be mounted by anysuitable means.

As the wheel I8 during the cutting operation rotates, it will be evidentthat it tends to carry any liquid that it may pick up into the guard. Toprevent this a stripper plate 48 is provided, this stripper plateextending laterally on opposite sides of the rear portion of the wheel.This plate may be mounted on the guard as indicated at 49 and maycomprise a single plate '48 with a narrow slot which affords justsuflicient clearance to permit the wheel to rotate. This plateefiectively strips from the wheel any liquid that may be carriedupwardly with it. Of course, the material to be cut must be held in theproper position in the container. Satisfactory means for doing this maycomprise the supporting blocks 52 and 53 separated by a narrow space topermit the abrasive wheel ii to pass between them. These blocks haveproperly shaped notches 55 to receive the work, which, in thedrawings'indicated, consists of a tube l3. These notches may be ofvarious shapes, but they are preferably tapered so that the work isfirmly held. Of

course, certain sections would be more stable in other shapes thanV-notche's, and, consequently, for particular Jobs the shape oi thenotches would be adapted accordingly. Manually oper-- ated means arealso provided for clamping or holding the work in these supportingblocks. In the present instance this clamping means comprises a lever 56pivoted at 51 to lugs 58 on the forward wall of the container l0, andthis lever includes a pair ofspaced arms 59 and 60 extending at theirfree ends over the blocks 52 and 53. They are spaced sufliciently topermit the wheel IE to pass between them, and these arms, with theblocks 52 and 53, provide means for clamping and holding the work onboth sides of the wheel. The handle GI permits lifting of the arms 59and .60 to release the work and also to control the movement of the arms59 and to the work holding position; It has been found advisable,however, when certain materials and shapes are being cut, to provideyielding resilient means for holding these clamps against the work. Thusthe lever 56 is provided with an arm 62 carrying adjustable screw 63threaded in the arm and engaging the end of a 'slidable block 64 mountedin a recess in the container III. In this recess isa spring 65 whichtends to force the block 64 out against the screw 63 and to clamp thearms 59 and 60 down on the work. After adjustment,

the screw 63 may be locked in adjusted posi-.

tion by lock-nut 6B, and itwill be evident that, with this construction,the tension of the spring may be adjusted, and, as a consequence, thepressure of the clamp on the work.

It has been found that in cutting glass tubes and particularly thin wallglass tubes, they should not be clamped too firmly. This adjustment ofthe pressure of the spring 65 is very effective in securing a properyielding resilient press re. It also seems advisable to have yieldingJesilient pads to contact with the work especially when glass tubes arebeing cut, and we further use such pads 61 preferably of live rubber orsimilar material. v

To the container Ill there is also aflixed a block 68 provided with apassage 69 having a curvature slightly greater than that of the wheel ad loca ed with its center of curvature approximately in the axis ofrotation of the wheel at the average position of the latter when cuttingthrough a section-thatis to say, the center of curvature of the conduitwouldordinarily be in the axis of rotation of the wheel when the latterhad about half out through the average section that the machine isdesigned to operate upon. The walls of the passage 59, it will be noted,are partially composed of the flanges I0 on either side of the wheel,these flanges extending toward each other to a waste pipe or circulatedby a pump for repeated use, if desired.

In using the machine, the materialwhich for purposes of illustration mayconsist of the glass tube l3is laid in the V-shaped notches of theblocks 52 and 53 and clamped therein by bringing the padsS-I down uponit. With'the wheel rotating in a counterclockwise direction, as viewedin Fig. l-that is, in a direction to carry down the conduit water led inthrough the pipe H, the wheel is brought down by manipulating the handle"a and the desired cut made. It is important that the conduit 69 be soconstructed .that the stream of water emerging from it shall impinge onan area which includes the point of entrance of the wheel into the cut,this region being sufliciently large to always include that point as thecutting progresses. Of course, it is obvious that for several reasons itis desirable that the wheel run in a fixed plane in order that lengthsof uniform thickness may be cut from rods, bars, sheets, and the like,and, furthermore, to avoid breakage. I It is therefore important thatthe cross-section area of the conduit be symmetrically designed withrespect to the plane of the wheel so that the pressure on both sides ofthe wheel will balance, since we have discovered that wheels of thegauge thickness that we employ are, when rotating at high speeds, easilydeflected sidewise by very slight unbalanced pressures on theirrespective faces. The velocity of the water or other liquid supplied tothe entrance end of the ,conduit need not be high since it derives avery high velocity by the centrifugal force imparted by the rapidlyrevolving wheel, the speed of which would vary from 1200 to 2500revolutions per minute, depending upon the length of the cut and thenature 01' the material being cut. The volume of the stream should,however, be sufliciently large so that the region covering andsurrounding the cut is virtually immersed in the liquid.

We claim:

1. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a member providedwith an arcual conduit for liquid mounted in the plane of rotation ofthe wheel and approximately concentric therewith, said conduit beingprovided with a narrow slot through which the edge of the wheel may,when tilted, extend into the conduit and rotate therein, said conduitbeing symmetrical with respect to the plane of travel of the wheeltherein.

2. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted,-the said frame bein pivotally wheel-bodily in its plane ofrotation, and a member provided with an arcual conduit for liquidmounted in the plane of rotation of the wheel and positioned todischarge liquid to the cutting region, said conduit being provided witha narrow slot through which the edge of the wheel may, when tilted,extend into the conduit and rotate therein.

3. In an abrasive cutting-machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel isrotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a member providedwith an arcual conduit for liquid mounted in the plane of rotation ofthe wheel and approximately concentric therewith, said conduit beingprovided with a narrow slot through which the edge of the wheel may,

into the conduit and rotate therein. I

4. In an abrasive cutting machine, means for clamping the'material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a mem berprovided with an arcual conduit for liquid mounted in the plane ofrotation of the wheel and approximately concentric therewith, saidconduit being provided with a slot ,through which the edge of the wheelmay, when tilted, extend into the conduit and rotate therein, saidconduit being symmetrical with respect to the plane of travel of thewheel therein.

5. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a member providedwith a conduit for liquid mounted in the plane of rotation of the wheeland positioned to discharge liquid to the cutting region,

' said conduit being provided with a narrow slot through which the'edgeof the wheel may extend into the conduit and rotate therein.

6. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive 5 mounted to permit it to tilt and to move the whentilted, extend wheel, a frame on which the said wheel is rotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a member providedwith a conduit for liquid mounted in the plane of rotation of the wheeland positioned to discharge liquid to the cutting region, said conduitbeing provided with a slot through which the edge of the wheel mayextend into the conduit and rotate therein.

7. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted, the said frame beingpivotally mounted to permit it to tilt andto move the wheel bodily in its'plane of rotation, and a member providedwith a arcual conduit for liquid mounted in the plane of rotation of thewheel and positioned to discharge liquid to the cutting region, saidconduit being provided with a slot through which the edge of the wheelmay, when tilted, extend into the conduit and rotate therein.

8. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a member providedwith an arcual conduit for liquid mounted in the plane of rotation ofthe wheel and approximately concentric therewith, said conduit beingprovided with a narrow slot through which the edge of the wheel mayextend into the conduit and rotate therein, said conduit beinsymmetrical with respect to the plane of travel of the wheel therein.

9. In an abrasive cutting machine, means for clamping the material to becut, a thin abrasive wheel, a frame on which the said wheel is rotatablymounted, the said frame being pivotally mounted to permit it to tilt andto move the wheel bodily in its plane of rotation, and a member providedwith an arcual conduit for liquid mounted in the plane of rotation ofthe wheel and approximately concentric therewith, said conduit beingprovided with a slot through which the edge of the wheel may extend intothe conduit and rotate therein, said conduit being symmetrical withrespect to the plane of travel of the wheel therein.

DAR'IREY LEWIS.

WIIFRID L. WALSH. WALTER vB. LASHAR, J a.

